300–150 ={#blank#}1{#/blank#}    300+105 ={#blank#}2{#/blank#}    80+120={#blank#}3{#/blank#}

315–200={#blank#}4{#/blank#}     800–600 ={#blank#}5{#/blank#}    205+50 ={#blank#}6{#/blank#}

5×2+24 ={#blank#}7{#/blank#}    16÷4+20 ={#blank#}8{#/blank#}    35 + 15-40 ={#blank#}9{#/blank#}

8000-4000{#blank#}1{#/blank#}7000-300    360+400{#blank#}2{#/blank#}460+300

750-600 {#blank#}3{#/blank#}750-60        540+400 {#blank#}4{#/blank#}900-50

400+700 {#blank#}5{#/blank#}300+800     890-40 {#blank#}6{#/blank#}980-40